Guillain-Barré Syndrome

Guillain-Barré syndrome is an acute, immune-mediated disorder of the peripheral nerves that causes rapidly progressive, usually symmetrical weakness and loss of reflexes, often following an infection. It is the most common cause of acute flaccid paralysis worldwide and can progress to respiratory failure, making it a neurological emergency despite the potential for substantial recovery.

Definition

Guillain-Barré syndrome is an acute, usually monophasic, immune-mediated polyradiculoneuropathy presenting with rapidly evolving symmetrical limb weakness and reduced or absent reflexes, frequently preceded by an infection and often accompanied by elevated cerebrospinal-fluid protein without pleocytosis.

Scope

This entry covers Guillain-Barré syndrome as a clinical entity: its post-infectious immune mechanism, the demyelinating and axonal subtypes, the typical ascending course with areflexia and cerebrospinal-fluid albuminocytological dissociation, the diagnostic criteria, and the general principles of monitoring and prognosis. It is a reference description and does not provide individualised diagnostic or treatment guidance.

Key concepts

• Acute flaccid paralysis
• Areflexia
• Ascending weakness
• Post-infectious immune trigger and molecular mimicry
• Demyelinating (AIDP) and axonal (AMAN/AMSAN) subtypes
• Albuminocytological dissociation in cerebrospinal fluid
• Respiratory and autonomic monitoring

Mechanisms

Guillain-Barré syndrome is usually triggered by an antecedent infection that provokes an immune response which cross-reacts with components of peripheral nerve, a process known as molecular mimicry. Depending on the target, the result is either demyelination, as in acute inflammatory demyelinating polyradiculoneuropathy, or primary axonal injury, as in the acute motor axonal forms. The immune attack on nerve roots and peripheral nerves produces the rapidly ascending weakness and areflexia, and inflammation of nerve roots contributes to the rise in cerebrospinal-fluid protein without a corresponding rise in cells.

Clinical relevance

Guillain-Barré syndrome is important to recognise because it evolves quickly and can compromise breathing and autonomic stability, so it is treated as a neurological emergency requiring close monitoring. This entry describes the syndrome for educational reference; it explains how the condition is understood and classified rather than offering individual diagnostic or treatment instructions.

Epidemiology

Guillain-Barré syndrome occurs worldwide with an incidence that rises with age and is somewhat higher in males. The demyelinating subtype predominates in Europe and North America, whereas axonal forms are relatively more common in parts of Asia and Latin America, reflecting differences in preceding infections and immune targets.

History

The syndrome takes its name from the 1916 description by Georges Guillain, Jean Alexandre Barré, and André Strohl, who noted acute paralysis with raised cerebrospinal-fluid protein and normal cell counts. Over the following century the condition was resolved into demyelinating and axonal subtypes, formal diagnostic criteria were established, and post-infectious immune mechanisms including molecular mimicry were characterised.

Seminal works

• asbury-cornblath-1990
• van-den-berg-2014
• willison-2016
• leonhard-2019

Frequently asked questions

Why is Guillain-Barré syndrome considered a medical emergency?

Weakness can progress over hours to days and may involve the muscles of breathing and the autonomic nervous system, so the condition requires close monitoring for respiratory and cardiovascular complications even though many people eventually recover.

What is albuminocytological dissociation?

It refers to the typical cerebrospinal-fluid finding in Guillain-Barré syndrome of raised protein with a normal or near-normal white-cell count, a pattern that helps support the diagnosis though it may be absent very early in the illness.